A hazard traditionally associated with outdoor activities such as gardening, hiking and camping has been the possibility of exposure to polyhydroxyaromatic skin irritants commonly found in plants such as, poison ivy, poison oak, poison sumac, and the like. The sap of such plants can cause an allergic reaction upon contact with the skin, despite the fact that the polyhydroxyaromatic skin irritant naturally occurs in low concentrations (e.g., 2-5% of the sap) and the contact is usually brief and incidental. The extent of reaction varies from individual to individual. Some individuals may experience little or no reaction or simply some itching which disappears after a few days, while others develop a severe skin rash which may require treatment with prescription antibiotics and/or prescription steroids and may need several weeks or even months to fully heal. Occasionally, exposure can lead to nephropathy and even to fatal systemic anaphylaxis.
The most common approach to this problem has been to avoid any contact with plants that contain the polyhydroxyaromatic skin irritants, which approach is extremely practical but not always workable under the circumstances. The leaves of poison ivy, poison oak or poison sumac for example, are similar to the foliage of other harmless plants and thus may not be readily distinguishable. The challenges to even skilled workers in the outdoors in identifying these plants is exemplified by the observation that 10% of lost work hours in the United States Forestry services is attributed to exposure to these poison plants. Various medications available for treating the effects of contact with plants that contain polyhydroxyaromatic skin irritants include a course of topical and/or enteric treatments with hydrocortisones, betamethasone, and other similar corticosteroids. Repeated exposure to the polyhydroxyaromatic skin irritants can result in a severe hypersensitive immunoreaction, that is often extremely painful and, occasionally, fatal.
Early treatment after exposure to the polyhydroxyaromatic skin irritant, that is before the onset of symptoms, is desirable. However, such treatment is predicated upon knowing that actual contact with the polyhydroxyaromatic skin irritant found in plants has occurred. Unfortunately contact with a polyhydroxyaromatic skin irritant does not result in an immediate skin irritation as one typically does not realize having been exposed to a polyhydroxyaromatic skin irritant until the symptoms develop some time after contact. It is not uncommon for the first symptom, typically itching, to manifest itself between about 6 hours and about 24 hours after contact. Additional symptoms, such as redness and swelling may not occur for up to 48 hours after contact, followed eventually by the formation of microblisters. There is a need to develop methods to promptly detect exposure to a polyhydroxyaromatic skin irritant found in the sap of plants.
There is a need in the art for new and more effective compositions and methods to promptly detect exposure to a polyhydroxyaromatic skin irritant found in the sap of plants. The invention is directed to these, as well as other, important ends.